Roundabouts have been a key form of junction in the UK for many years. They are used on all classes of road in both urban and rural areas for the efficient and safe control of traffic, particularly where side road flows are high. Roundabouts are heavily used throughout the UK's trunk and principal road network, as well as on local authority roads.

The report presents an international review of roundabout design standards and guidelines that was undertaken to inform the revision the UK Geometric Design Standard for Roundabouts (TD 16/93 at the time of this review). Provision for pedestrians and cyclists was of particular concern. A design hierarchy for roundabouts is proposed for the revised Standard, to depend on road type, whether the speed limits on the approach roads exceed 40mph and on the levels of vehicle and non-motorised user flow. A “compact” (continental-style) roundabout is proposed for low flow roads, with single lane entries, exits and circulatory carriageway. In urban areas, this would have tighter geometry than normal roundabouts, and outward crossfall.

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